Closure system with distinct breaking forces

ABSTRACT

A closure system includes a first unit that includes a base presenting two opposite faces, a first retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base. The closure system also includes a second unit comprising a base presenting two opposite faces, a second retaining element arranged on the first face of the base and adapted to engage the first retaining element, and a bonding layer arranged on the second face of the base. The closure system is characterized in that the bonding layer of at least one of said units comprises two bonding portions presenting distinct breaking forces.

GENERAL TECHNICAL FIELD

The present invention relates to the field of closure systems, findingits application in particular in making reclosable bags, or moregenerally for products requiring an attachment or closure system that isreusable, in particular in the food industry, and also in the medical orhygiene field.

STATE OF THE ART

Reusable closures are commonly used in numerous domains, and they may bemade in several ways.

Thus, by way of example, closures are known that are made by means ofcomplementary section members arranged on two elements that are to beassembled together, or closures are known that are made by means ofloop-and-hook or indeed hook-and-hook type systems that form unitscommonly referred to as self-gripping units, i.e. units in which thehooks and loops attach together reversibly on being put into contact.

A recurring problem with such closures is to ensure that the closedstate is well maintained, while still being easy for a user to open andclose.

Several types of closure element have thus been proposed, in order tomake connections having a profile that is asymmetric; the force requiredfor separating such a connection depends in particular on the type ofeffort that is exerted.

Furthermore, closure systems must be capable of being assembled on theintended product, which leads to major requirements in terms of guidanceand strength during assembly on an article.

Finally, closure systems must be supplied that are free of anycontamination, in particular in the fields of hygiene and food, inparticular in the light of certain standards, such as the BRC/IOPstandard for the food industry.

SUMMARY OF THE INVENTION

The present invention seeks to propose a closure system satisfying thesevarious problems, at least in part, and thus proposes a closure systemcomprising:

-   -   a first unit comprising a base presenting first and second        opposite faces, a first retaining element arranged on the first        face of the base, and a bonding layer arranged on the second        face of the base and adapted to enable the first unit to be        secured on a support surface; and    -   a second unit comprising a base presenting first and second        opposite faces, a second retaining element arranged on the first        face of the base, and a bonding layer arranged on the second        face of the base and adapted to enable the second unit to be        secured on a support surface;

the first and second retaining elements being configured to engage insuch a manner as to make a reclosable connection;

the system being characterized in that the bonding layer of at least oneof said units comprises two bonding portions, each configured to securesaid units on a support surface, and presenting distinct breakingforces.

The closure system optionally presents one or more of the followingcharacteristics, taken independently or in combination:

-   -   the bonding layer of at least one of said units includes empty        portions such that the bonding portions of said at least one        unit are disjoint in full or in part; at least one of the empty        portions may then define a closed cavity, including a sensory        marker;    -   each unit further comprises a soleplate forming a support        surface, each base being secured to a first face of the        associated soleplate by means of its bonding layer; said bonding        layers are then made by way of example by heat-sealing said        units on the soleplates;    -   in a variant of the above characteristics, said at least one        closed cavity is defined by the base, the soleplate, and the        bonding portions of the unit under consideration;    -   for said at least one unit having two bonding portions        presenting distinct breaking forces, the bonding portions define        two distinct breaking forces Fr1 and Fr2, and the retaining        elements define an opening force F, with said forces being such        that Fr1<F<Fr2;    -   each of said retaining elements is formed integrally with the        associated base, and where appropriate also with the associated        bonding layer;    -   said retaining elements comprise fields of retaining elements,        at least one of said retaining elements comprising hooks;    -   at least one of said retaining elements comprises a section        member extending in a longitudinal direction;    -   the first and second units are joined, forming a single unit;        and    -   the bonding layer of each of said units comprises at least two        bonding portions presenting distinct breaking forces.

The invention also provides a container having two side walls definingan opening giving access to an inside volume, said container including aclosure system as defined above arranged on its side walls so as to forma reclosable opening.

In another particular embodiment, each unit has an internal border andan external border, the internal border being arranged in the insidevolume of the container, and the external border being arranged outsideof the inside volume of the container, the bonding layer of at least oneof the units comprising an inner portion and an outer portion presentingdistinct breaking forces, and is configured so that its inner portionpresents a breaking force that is smaller than the breaking force of itsouter portion.

In another particular embodiment, each unit has an internal border andan external border, the internal border being arranged in the insidevolume of the container, and the external border being arranged outsideof the inside volume of the container, the bonding layer of at least oneof the units comprises an inner portion and an outer portion presentingdistinct breaking forces, and is configured in such a manner that itsouter portion presents a breaking force that is smaller than thebreaking force of its inner portion.

In another particular embodiment, each unit has an internal border andan external border, the internal border being arranged in the insidevolume of the container, and the external border being arranged outsideof the inside volume of the container, the bonding layer of each of theunits comprise an inner portion and an outer portion presenting distinctbreaking forces, the bonding layer of one of the units is configured sothat its outer portion presents a breaking force smaller than thebreaking force of its inner portion, and the bonding layer of the otherunit is configured in such a manner that its inner portion presents abreaking force less than the breaking force of its outer portion. Moreparticularly, the bonding portion presenting a smaller breaking force islocated at least in part in a zone defined by the projection of thefirst and/or second retaining elements.

SUMMARY OF THE FIGURES

Other characteristics, objects, and advantages of the invention appearfrom the following description, which is purely illustrative andnon-limiting, and which should be read with reference to theaccompanying drawings, in which:

FIG. 1 shows an example of a system in an aspect of the invention;

FIG. 2 shows another example of a system in an aspect of the invention;

FIGS. 3 to 10 show various other examples of systems in an aspect of theinvention in association with a container such as a bag; and

FIGS. 11 and 12 are graphs illustrating the effect of the system asdescribed.

In the figures, elements that are in common are identified by numericalreferences that are identical.

DETAILED DESCRIPTION

FIG. 1 shows an example of a system in an aspect of the invention.

This figure shows a closure system comprising two units 100 and 200adapted for making a reclosable connection.

Each unit comprises a base having first and second opposite faces, aretaining element arranged on the first face of the base, and a bondinglayer arranged on the second face of the base and adapted to enable theunit to be secured on a support surface.

Thus the first unit 100 has a base 110 presenting first and second faces112 and 114 that are opposite, a retaining element 120 arranged on thefirst face 112 of the base 110, and a bonding layer 130 arranged on thesecond face 114 of the base 110 and adapted to enable the first unit 100to be secured on a support surface, not shown in this figure.

Likewise, the second unit 200 comprises a base 210 presenting first andsecond faces 212 and 214 that are opposite, a retaining element 220arranged on the first face 212 of the base 210, and a bonding layer 230arranged on the second face 214 of the base 210 and adapted to enablethe second unit 200 to be secured on a support surface, not shown inthis figure.

The bonding layers 130 and 230 may be of any type, and in particularthey may be made by gluing or by heat-sealing with or without addedmaterial.

The retaining elements 120 and 220 of the first and second units areconfigured to engage each other in such a manner as to make a reclosableconnection, e.g. of the self-gripping or contact-closure type.

In the example shown, the retaining elements 120 and 220 are fields ofhooks or the equivalent, thus forming a male-male type connection, suchthat putting the two retaining elements 120 and 220 into contact andpossibly applying pressure thereon causes them to become mutuallyengaged.

The retaining elements 120 and 220 may extend independently over theentire width of their bases 110 and 210, they may have a plurality offields of retaining elements, or they may have a single field ofretaining elements, as shown in the figures.

The retaining elements 120 and 220 may be of any type, in particularcontinuous units made by extrusion, fields of discrete elementspotentially extending in parallel longitudinal lines or indeed beingarranged in a staggered configuration, or a combination of continuousunits and discrete fields of elements. Various other embodiments aredescribed below. The retaining elements 120 and 220 may be formedintegrally with the associated bases.

The first and second units 100 and 200 may also form a single unit, asexplained below with reference to FIG. 10. The retaining elements 120and 220 then typically define a portion of that single unit that isadapted to break on application of an external or internal force as afunction of the application.

Such an embodiment is particularly advantageous for example when appliedto a bag, and more particularly for a pouring spout or indeed when theunit is applied continuously to the entire perimeter of the bag.

As shown in FIG. 1, the bonding layer of at least one of the units 100and 200 comprises two bonding portions presenting distinct breakingforces.

In the example shown, the bonding layer 130 of the first unit 100comprises two distinct bonding portions 132 and 134 that presentdistinct breaking forces. Each of these bonding portions 132 and 134 isarranged between the first unit 100 and the support surface so as tomake a connection between the second face 114 of the base 110 of thefirst unit 100 and the support surface. These two bonding portions 132and 134 are disjoint; they extend facing distinct areas of the base 110of the first unit 100. The term “facing distinct areas” is used to meanthat the projections of the bonding portions 132 and 134 onto the base110 in a direction normal to the second surface 114 of the base 110 aredistinct and do not overlap.

The term “distinct breaking forces” is used to mean that these twobonding portions 132 and 134 are adapted to secure one of the units,specifically the first unit 100, on a support surface, and to do sowhile opposing given resistance to a force applied thereto.

In this example, the two bonding portions 132 and 134 are configured soas to make connections that present distinct breaking forces, i.e. sothat when a given force is applied to the first unit, one of the bondingportions 132 or 134 may break while the other portion 134 or 132 remainsunchanged and maintains the connection between the unit 100 and thesupport surface.

The different bonding portions in a single bonding layer may be madeusing materials and methods that are identical or different.

The bonding portions in a given bonding layer may be made integrallywith the associated base. As mentioned, the figures show the inventionin diagrammatic manner. Specifically, the borders (the interfacesbetween two bonding portions defining distinct breaking forces orinside/outside borders (in the presence of a sealed cavity)) couldpresent a shape in section that is inclined, for example, or in theshape of a letter U turned through 90′; the width of the bonding layermay be less than the width of the base, or indeed at least one of theopposite ends of the second face 114 of the base 110 of the first unitcould define a portion that does not have any adhesive material (orbonding zone/connection).

In the example shown in FIG. 1, the second unit 200 has a bonding layer230 that is substantially uniform, presenting a breaking force that islikewise uniform.

As explained below, other embodiments are possible; the bonding layer230 of the second unit could equally well present a plurality of bondingportions presenting distinct breaking forces.

The bonding portions 130 and 230 may be made using different methods;for example, by applying an adhesive or meltable material, byheat-sealing, by gluing, by diffusion, or by any other appropriatemethod.

In order to illustrate the operation of the system shown in FIG. 1, itis assumed that the bonding portion 134 adheres with a breaking forcethat is smaller than that needed for the bonding portion 132, and alsosmaller than that needed for the bonding layer 230.

Once the two units 100 and 200 have been secured to support surfaces, auser engages the retaining elements 120 and 220 so as to connect the twounits 100 and 200 together. As example applications, mention may be madein particular of bags in the food industry field, or sanitary articlessuch as diapers.

Once the retaining elements 120 and 220 have been engaged, theirconnection is subjected to various stresses, as a result in particularof the way the article in question is used.

For the connection they provide, the retaining elements 120 and 220define a strength beyond which the retaining elements 120 and 220 becomeseparated from one another, with this strength being written F.

As mentioned above, at least one of the units 100 and 200 has a bondinglayer made up of two portions defining two distinct breaking forces forthe unit in question relative to the support surface.

Thus, by way of example, if it is considered that these two portionsdefine two distinct breaking forces Fr1 and Fr2, where Fr1<Fr2, it isthen possible to distinguish various particular circumstances.

In a first configuration, the forces Fr1, Fr2, and F are such thatFr1<F<Fr2.

Thus, after first closure, the system is such that on first opening theforce that is applied begins by breaking one of the portions of thebonding layer (when applying a force of at least Fr1) prior toseparating the units 100 and 200 (on applying a force at least equal toF).

Thus, on first use, the properties of the closure system are modified,and the breaking of one of the portions of the bonding layer creates ahinge-type structure in at least one of the units, as shown in figuresthat are described below.

Assuming then that the bonding portion 134 provides bonding with abreaking force (Fr1) that is less than the breaking force (Fr2) achievedby the bonding portion 132, then on first opening of the system, it isthe bonding portion 134 that breaks. The portion of the base 110 thatwas initially secured by the bonding portion 134 on a support surfacethen becomes separated, forming a hinge portion.

By way of example, the bonding portion 132 may be made by heat-sealing,while the bonding portion 134 may be made by gluing. In a variant, bothof the bonding portions 132 and 134 may be made by heat-sealing, withthe material and methods used then defining distinct strengths, e.g.different heat-sealing temperatures, different pressures, differentcontact times, or indeed a combination of several of these parameters.In a variant, the two bonding portions 132 and 134 may be made bygluing, with the materials and methods used then defining distinctstrengths.

The bonding layer 230 defines a breaking force greater than the force F,thereby securing the second unit 200 on a support while using theclosure system. In a variant, the breaking force of the bonding layer230 and the breaking force of the bonding portion 132 could be similar.

Such a configuration presents several advantages.

It thus makes it possible to form a closure system having propertiesthat are asymmetrical, e.g. so that the force needed to open the closuresystem differs depending on the point of application. For example withsuch a closure system arranged on a bag, the force required for openingthe bag from its inside may be different, e.g. greater, than the forcerequired for opening the bag from its outside.

Furthermore, such a configuration makes it possible to provide a markerindicating whether the closure system has already been opened or not.

In addition, by modifying the properties of the closure system in thisway on its first use, but not from the very beginning, it is possible tosimplify its fabrication and integration on a product.

In a second configuration, the forces Fr1, Fr2, and F are such thatFr1<Fr2<F.

In such a configuration, on first use of the closure system, the bondingportions break in succession before the retaining elements 120 and 220separate.

Thus, the proposed system provides a closure of the tamperproof type,which breaks on first opening.

The presence of two bonding portions 132 and 134 having distinctbreaking forces makes it possible both to spread out the opening of thesystem, and also to propose properties that are asymmetric, e.g. so thatthe system presents distinct strengths as a function of the applicationpoint at which the force is applied.

FIG. 2 shows a particular embodiment of the system described above withreference to FIG. 1.

The description below relates solely to elements that distinguish theembodiment of FIG. 2 from that of FIG. 1.

In this embodiment, the bonding layer 130 of the base 110 of the firstunit 100 defines an empty portion between the bonding portions 132 and134.

More precisely, in the embodiment shown, the bonding portions 132 and134 form strips arranged along two opposite ends of the second face 114of the base 110 of the first unit 100, these two strips being disjoint,thereby defining a portion that does not have any adhesive material.

Thus, on breaking one of the bonding portions, the first unit 100 isheld on a support surface by only one bonding strip corresponding to thebonding portion 132, thereby forming a hinge presenting greateramplitude than in the embodiment described above.

FIGS. 3 to 10 show various example applications of a closure system inan aspect of the invention.

FIGS. 3 and 4 show an example container having a closure system asdescribed above. The container as shown is of the bag type and comprisestwo connected-together walls 1 and 2 defining an inside volume 3 and anopening 4, the closure system being arranged so as to close the opening4.

In this example, the units 100 and 200 are similar to those describedabove with reference to FIG. 1.

Each of the two units 100 and 200 is secured to a respective wall 1 or 2of the container via their respective bonding layers 130 and 230.

As shown in FIG. 3, one of the units, specifically the unit 100, has abonding layer 130 presenting two bonding portions 132 and 134 thatdefine distinct breaking forces, as described above with reference toFIG. 1.

The bonding layer 230 defines a breaking force greater than the force F,thereby ensuring that the second unit 200 is secured to a support,specifically the wall 2 of the container, while the closure system is inuse.

It is assumed at this point that the bonding portion 134 defines abreaking force Fr1 and the bonding portion 132 defines a breaking forceFr2 such that Fr1<Fr2.

It is also assumed that the retaining elements 120 and 220 define aconnection between the two units 100 and 200 that is configured towithstand a force F, such that Fr1<F<Fr2.

The system can be assembled on the container before or after thecontainer is filled. By way of example, the container may be filled, andthen the system may be secured thereto with its two units 100 and 200optionally engaged, or indeed the two units 100 and 200 may be securedindependently to the container, the container may be filled, and thenthe two units may be engaged in order to close the container.

The use of such a container is described below.

Before first opening, the two units 100 and 200 are secured respectivelyto the walls 1 and 2 of the container via their bonding layers 130 and230.

Various circumstances can then be distinguished.

When the user seeks to open the container in order to access itscontents, the user applies a force on the walls 1 and 2 of the containertending to move them apart so as to disengage the retaining elements 120and 220.

This force is usually applied via the free ends of the container, i.e.the ends of the walls 1 and 2 of the container that define its opening4. These ends may include means for facilitating user grip (not shown),e.g. striations. Thus, if the applied force is greater than the force F,the retaining elements 120 and 220 disengage, and the container isopened. Where appropriate, during disengagement of the retainingelements 120 arranged in register with the bonding portion 134, thatportion breaks totally or in part.

Conversely, if a force is applied on the closure system from the insideof the container, e.g. as a result of the container being droppedthrough a height of one meter, then the applied force begins by breakingthe bonding portion 134, thereby separating a portion of the base 110from the wall 1, so as to form a hinge-type structure, as shown in FIG.4. Such a hinge-type structure increases the strength of the closuresystem against stress exerted from the inside of the container, andconsequently reduces any risk of the container opening accidentally.

Such a container thus presents greater strength against opening from theinside of the container than from its outside, while still enabling thecontainer to be opened from the outside in simple manner.

FIGS. 5 and 6 show a variant of the embodiment described above withreference to FIGS. 3 and 4, in which each of the two units 100 and 200is secured to a respective soleplate 140 or 240, forming supports forthe units 100 and 200. These two soleplates 140 and 240 are themselvessecured to the walls 1 and 2 of the container, e.g. by heat-sealing, bygluing, or by any other appropriate means.

In the embodiment shown, the soleplates 140 and 240 extend beyond theunits 100 and 200, and the soleplates 140 and 240 are thus secured tothe walls 1 and 2 via connections that are made on either side of theunits 100 and 200, being offset away from the units 100 and 200.

Thus, while securing the soleplates 140 and 240 fitted with the units100 and 200 on the walls 1 and 2, it is possible for example to applypressure or heat for making these connections without damaging the units100 and 200, and in particular the retaining elements 120 and 220.

The closure system may thus be supplied fitted with such soleplates 140and 240 in order to facilitate assembly on a product such as a containeror a sanitary article and at a high rate of assembly.

As shown in FIG. 5, one of the units, specifically the unit 100, has abonding layer 130 presenting two bonding portions 132 and 134 thatdefine distinct breaking forces, as described above with reference toFIG. 1.

The bonding layer 230 defines a breaking force that is greater than theforce F, thus ensuring that the second unit 200 is secured to a supportwhile the closure system is in use.

It is assumed at this point that the bonding portion 134 defines abreaking force Fr1 and the bonding portion 132 defines a breaking forceFr2, such that Fr1<Fr2.

It is also assumed that the retaining elements 120 and 220 define aconnection between the two units 100 and 200 that is configured toresist a force F, such that Fr1<F<Fr2.

The soleplates 140 and 240 are secured to the walls 1 and 2 of thecontainer in such a manner as to present strength that is strictlygreater than that of the bonding layers of the units 100 and 200, andthan the strength of the connection defined by the retaining elements120 and 220, such that the soleplates 140 and 240 remain secured to thewalls 1 and 2 while the system is in use.

When the system has soleplates 140 and 240 forming supports for theunits 100 and 200, the system can be assembled on the container beforeor after filling the container. For example, it is possible to fill thecontainer and then secure the system thereto, with its two units 100 and200 optionally already mutually engaged, or else the two units 100 and200 can be secured independently to the container, the container can befilled, and then the two units can be engaged so as to close thecontainer.

There follows a description of the use of such a container.

Prior to first opening, both units 100 and 200 are secured to theirrespective soleplates 140 and 240 via their bonding layers 130 and 230.

Various circumstances can be distinguished.

When the user desires to open the container in order to access itscontent, the user applies a force to the walls 1 and 2 of the container,tending to move them apart, so as to disengage the retaining elements120 and 220.

This force is usually applied via the free ends of the container, i.e.the ends of the walls 1 and 2 of the container that defines its opening4. Thus, if the applied force is greater than the force F, the retainingelements 120 and 220 disengage and the container is opened. Whenappropriate, during disengagement of the retaining elements 120 arrangedin register with the bonding portion 134, that portion breaks totally orin part.

Conversely, if the force is applied to the closure system from theinside of the container, e.g. as a result of the container droppingthrough a height of one meter, the applied force begins by breaking thebonding portion 132, thereby separating a portion of the base 110 fromthe soleplate 140 so as to form a hinge-type structure, as shown in FIG.6. Such a hinge-type structure increases the strength of the closuresystem against stress exerted from the inside of the container, andconsequently reduces the risk of the container opening accidentally.

Such a container thus presents greater strength against opening from theinside of the container than from its outside, while still allowing thecontainer to be opened simply from the outside, and while presentingassembly that is simplified.

FIG. 7 shows another embodiment of a container including a closuresystem in an aspect of the invention.

In this embodiment as shown, the retaining elements 120 and 220 of thetwo units 100 and 200 are section members having complementary shapes.It will readily be understood that fields of discrete elements as shownin FIGS. 5 and 6, or of any other type of retaining element could alsobe used.

In this embodiment, the two units 100 and 200 are secured to thesoleplates 140 and 240 via bonding strips arranged along the inside andoutside edges of the bases 110 and 210 of the units 100 and 200. Thesebonding strips thus define an empty portion between each base and theassociated soleplate, as descried above with reference to the first unit100 shown in FIG. 2.

In the examples shown, the two bonding portions 132 and 134 connectingthe first base 110 to the soleplate 140 are distinct, as described abovewith reference to FIG. 2. The two bonding portions 232 and 234connecting the second base 210 to the soleplate 240 are likewisedistinct, and they define distinct breaking forces, respectively Fr3 andFr4 for the bonding portions 234 and 232, such that Fr3<F<Fr4, where Fis the force needed to disengage the retaining elements 120 and 220. Theforces Fr1 and Fr3 are typically identical, as are the forces Fr2 andFr4, providing the bonding portions 132 and 134 are identical to thebonding portions 232 and 234, respectively.

It should be observed that the bonding portion 234 presenting smallerstrength in this example is arranged towards the outside of thecontainer.

Thus, when a user applies a force to open the container via the freeedges of the container, this bonding portion 234 breaks, thus making itpossible in particular to form a marker that the container has beenopened, or indeed to increase the strength of the closure system againstopening while simplifying assembly thereof, e.g. on the walls of acontainer or on any other product.

The bonding portion 134 breaks in the event of a force greater than Fr1being applied from the inside of the container, thereby protecting thecontainer against risks of accidental opening, as mentioned above.

The proposed structure thus makes it possible to form a structure havingtwo hinges, with one of the units, the unit 100, being connected to thecontainer via its outer border, while the other unit 200 is connected tothe container by its inner border.

The empty portions formed between the bases and the soleplates may thenbe completely closed, so as to form sealed cavities. In the embodimentshown, it can be understood that breaking the bonding portion 134 leadsto opening the sealed cavity formed between the base 110 and thesoleplate 140. Likewise, breaking the bonding portion 234 leads toopening the sealed cavity formed between the base 210 and the soleplate240.

It is then possible, by way of example, to arrange a sensory marker insuch an empty portion, e.g. a marker that is visible or olfactory, andthat is thus released on first use of the closure system, therebyforming an additional usage marker.

FIG. 8 shows yet another embodiment of a container including a closuresystem in an aspect of the invention.

In the embodiment shown, the retaining elements 120 and 220 are of theloop-and-hook type. As above, it can be understood that fields ofdistinct elements as shown in FIGS. 5 and 6, or of any other type ofretaining element could be used, and that this particular example ofretaining elements is merely illustrative.

In this embodiment, the first unit 100 is secured to the soleplate 140via a uniform bonding layer 130 serving to hold the first unit 100 onthe soleplate 140 when the system is in use.

The second unit 200 is secured to the soleplate 240 via a bonding layer230 comprising two distinct bonding portions 232 and 234, similar tothose described above with reference to FIG. 7.

The two bonding portions 232 and 234 thus define distinct breakingforces, respectively Fr3 and Fr4 for the bonding portions 234 and 232,such that Fr3<F<Fr4, where F is the force needed to disengage theretaining elements 120 and 220.

Thus, when a user applies an opening force on the container via the freeborders of the container, this bonding portion 234 breaks and forms amarker indicating that the container has been opened.

It should be observed that the various embodiments described in FIGS. 1to 8 define only two distinct bonding portions. It will readily beunderstood that such examples are not limiting, and that multiplebonding portions defining distinct breaking forces could be provided,providing at least one of the bonding layers of one of the units 100 and200 includes at least two bonding portions defining distinct breakingforces.

FIG. 9 thus shows another embodiment of a container including a closuresystem in an aspect of the invention.

This embodiment is similar to the embodiment described above withreference to FIG. 5, and differs therefrom by the fact that the bondinglayer 130 in this embodiment comprises three distinct portions,respectively 132, 134, and 136, that are adapted to secure the firstunit 100 on a support while defining at least two distinct breakingforces.

Thus, it is assumed that the bonding portion 132 arranged between thebonding portions 134 and 136 defines a breaking force Fr5, the bondingportion 134 arranged along the inside edge of the unit 100 defines abreaking force Fr6, and the bonding portion 136 arranged along theoutside edge of the unit 100 defines a breaking force Fr7.

By way of example, these breaking forces are configured in such a mannerthat Fr6<F<Fr5, and Fr7<F<Fr5.

Thus, during first use of the opening system, the bonding portion 136breaks to form a marker that the container has been used.

The bonding portion 134 likewise serves to reduce the risk of thecontainer opening accidentally, as described in detail above withreference to FIG. 5. By way of example, the forces Fr6 and Fr7 may beequal or they may be different.

In a variant, the breaking forces may be configured in such a mannerthat Fr6<Fr5<F<Fr7.

In such an embodiment, the bonding portions 134 and 132 break insuccession on application of a force from the inside of the container.The bonding portion 136 serves to maintain the connection between thebase 110 and the soleplate 140 with a hinge-type connection similar tothat shown in FIG. 6.

The inverse configuration is possible, e.g. by configuring the breakingforces such that Fr7<Fr5<F<Fr6.

The bonding portions 136 and 132 then defines two successive markersthat the system has been opened, while the bonding portion 134 serves tomaintain the connection between the base 110 and the soleplate 140 witha hinge-type connection.

FIG. 10 shows another embodiment of a container including a closuresystem in an aspect of the invention.

In the embodiment shown, the container has an opening 4 defining apouring spout, that can be selectively opened or closed by means of theclosure system comprising the units 100 and 200 arranged on the walls 1and 2 of the container. In this example, the two units 100 and 200 forma single continuous unit, and they are typically identical.

The presently-proposed closure system serves to ensure that the pouringspout formed in this way has improved control over its strength againstopening, and to improve its strength against accidental opening, e.g. inthe event of the container being dropped. The closure system as shown inFIG. 10 does not have a soleplate in this example. In a variantembodiment, the closure system could include a soleplate as describedabove.

The closure system presents a similar advantage when the units 100 and200 are applied continuously all around the perimeter of the opening ofa container.

In the various embodiments, the term “heat-sealing” is used for exampleto cover bonding by macromolecular diffusion of the type involvingultrasound, heat, or indeed ultrafrequencies.

In the various embodiments, the opening force F of the bag lies forexample in the range 0.1 newtons (N) to 200 N, and more particularly inthe range 0.5 N to 100 N, and still more particularly in the range 1 Nto 60 N.

In the various embodiments, the base, the retaining elements, and thesoleplates of the units 100 and 200 are preferably made using one (ormore) polymer materials or plastics materials, e.g. linear low densitypolyethylene (LLDPE), low density polyethylene (LDP), metallocenepolyethylene (m-PE), high density polyethylene (HDPE), ethylene vinylacetate (EVA), and polypropylene (PP), having a molecular weightdistribution that is unimodal or multimodal (e.g. bimodal), inparticular a composition comprising LLPDE and a plastomer, in particulara polyethylene-based plastomer. It should be understood that the basesand/or the soleplates of the units 100 and 200 are preferably made up ofa plurality of polymer materials or plastics materials, and that thevarious materials in the base and/or the soleplate may be distributeduniformly or non-uniformly (e.g. in the form of different layers, eachhaving a different material recipe).

In the various embodiments, the base, the retaining elements, and thesoleplate may comprise a single material or at least two materialshaving different melting temperatures, in particular meltingtemperatures that differ by at least 5° C., or more particularly meltingtemperatures that differ by at least 20° C. The melting temperatures ofthe materials forming the base, the retaining elements, and thesoleplate may be different or identical and they may lie in the range50° C. to 250° C., and more particularly in the range 60° C. to 170° C.

In the various embodiments, bonding portions defining distinct breakingforces should be understood as meaning that the breaking forces differby at least 5%, more particularly by at least 10%, preferably by atleast 20% of the weaker breaking force.

In the examples described, the bonding portions are continuous in thelongitudinal direction in which the retaining elements 120 and 220extend in their machine direction (MD), i.e. the direction in which theretaining elements are transported at the end of their fabrication, orelse in the cross-direction (CD), i.e. the direction perpendicular tothe machine direction, depending on the method of fabrication used. In avariant embodiment, the bonding portions may be made discontinuously inthe longitudinal direction and/or in a lateral direction perpendicularlyto the longitudinal direction.

FIGS. 11 and 12 are two graphs showing the effect of the system asdescribed.

These two graphs plot the variation of the force (in newtons) as appliedto two opposite walls fitted with a closure system during movement (inmillimeters and plotted along the abscissa axis). FIG. 11 show theresults obtained with a closure system as described above, while FIG. 12shows the results obtained with a prior art closure system.

The measurements were taken by fastening the two units forming each ofthe closure systems on two support surfaces, typically walls of acontainer such as a plastic bag.

Those two support surfaces were then arranged in two jaws of a tractionmachine that applied a traction force seeking to separate the two unitsof the closure system, thereby simulating opening of a container fittedwith such a closure system.

FIG. 11 shows two curves, representing two successive “openings” of thesame closure system in an aspect of the invention.

The curve C1 thus represents the first opening of the system, and thecurve C2 the second opening of the system.

The force was applied so as to simulate an opening force applied to theclosure system in a “non-desired” direction, e.g. corresponding to anopening force applied from the inside of a bag, as described above withreference to FIGS. 3 and 4.

As can be seen clearly in FIG. 11, the two curves C1 and C2 present amain peak going up to a force of about 35 N.

Unlike the curve C2, the curve C1 presents a first peak of smalleramplitude (about 10 N) slightly ahead of the main peak.

The first peak corresponds to applying a force and then breaking one ofthe bonding portions of the closure system.

The main peak corresponds to opening the closure system after breakingone of the bonding portions of the closure system.

It can thus be seen that the closure system behaves differently on firstuse (curve C1) and on subsequent uses (curve C2); only the first usepresents the first peak corresponding to breaking a bonding portion.FIG. 12 shows two curves D1 and D2, both representing two successive“openings” of a single closure system having retaining elementsidentical to those used for obtaining the graphs of FIG. 11, butfastened to the support surface in conventional manner, i.e. with abonding layer that is uniform and configured not to break during use ofthe closure system.

As can be seen in this figure, the two curves D1 and D2 have similarprofiles, each presenting a succession of peaks of diminishing intensity(in the range about 1 N to about 7 N) representing the progressiveseparation of the retaining elements until complete opening.

It can be seen firstly that unlike the curves shown in FIG. 11, the twocurves D1 and D2 have similar profiles, and thus that the closure systempresents properties that are substantially constant on first opening andon subsequent openings, unlike the system of the invention, whichpresents properties that are distinct on first opening, compared withsubsequent openings.

It can also be seen that the peaks of the curves D1 and D2 are ofamplitude that is considerably smaller than the amplitude of the peaksof curves C1 and C2, even though the retaining elements used areidentical.

The system of the invention thus makes it possible to obtain propertiesof strength against opening that are greatly increased in apredetermined direction. It should also be observed that opening asystem of the invention by applying a force in a “desired” direction,e.g. from the outside of a bag, would lead to curves similar to thecurves D1 and D2 when using the embodiments of FIGS. 3 to 6. The systemas described thus makes it possible to increase greatly the strength ofthe closure system against opening in the event of a force being appliedin a first direction, e.g. corresponding to non-desired use of theclosure system that would lead to accidental opening, while maintainingstrength against opening substantially unchanged when applying a forcein a second direction, e.g. corresponding to “normal” and desired use ofthe closure system.

The proposed closure system makes it possible to provide a closure withproperties that are asymmetric, but that is easy to make and assemble ona support.

Furthermore, the proposed system is advantageous in terms of hygienecompared with conventional asymmetric closure systems; the bondingportion that is configured to break on use makes it possible inparticular to avoid accumulating impurities in comparison with a systemin which such a bonding portion is not present and where a hinge-typeasymmetric connection is present from the beginning, thus forming acorner in which impurities can accumulate.

The system proposed is also very flexible in terms of applications, andmakes it possible to provide asymmetric closure systems presentingmarkers of opening or indeed tamperproofing. The bonding portionconfigured to break during opening may for example be configured toleave residual marks (e.g. locally increased roughness, surfaceasperities, or surface whitening when the material is transparent) on atleast one of the faces formed as a result of this bonding portionbreaking, thereby forming an opening marker.

1. A closure system comprising: a first unit comprising a basepresenting first and second opposite faces, a first retaining elementarranged on the first face of the base, and a bonding layer arranged onthe second face of the base and adapted to enable the first unit to besecured on a support surface; and a second unit comprising a basepresenting first and second opposite faces, a second retaining elementarranged on the first face of the base, and a bonding layer arranged onthe second face of the base and adapted to enable the second unit to besecured on a support surface; the first and second retaining elementsbeing configured to engage in such a manner as to make a reclosableconnection; the system being characterized in that the bonding layer ofat least one of said units comprises two bonding portions, eachconfigured to secure said units on a support surface, and presentingdistinct breaking forces.
 2. The system according to claim 1, whereinthe bonding layer of at least one of said units includes empty portionssuch that the bonding portions of said at least one unit are disjoint infull or in part.
 3. The system according to claim 2, wherein at leastone of the empty portions defines a closed cavity, including a sensorymarker.
 4. The system according to claim 1, wherein each unit furthercomprises a soleplate forming a support surface, each base being securedto a first face of the associated soleplate by means of its bondinglayer.
 5. The system according to claim 4, wherein said bonding layersare made by heat-sealing said units on the soleplates.
 6. The systemaccording to claim 1, wherein: for said at least one unit having twobonding portions presenting distinct breaking forces, the bondingportions define two distinct breaking forces Fr1 and Fr2; and theretaining elements define an opening force F; said forces being suchthat Fr1<F<Fr2.
 7. The system according to claim 1, wherein each of saidretaining elements is formed integrally with the associated base.
 8. Thesystem according to claim 1, wherein each of said retaining elements isformed integrally with the associated base and the associated bondinglayer.
 9. The system according to claim 1, wherein said retainingelements comprise fields of retaining elements, at least one of saidretaining elements comprising hooks.
 10. The system according to claim1, wherein at least one of said retaining elements comprises a sectionmember extending in a longitudinal direction.
 11. The system accordingto claim 1, wherein the first and second units are joined, forming asingle unit.
 12. The system according to claim 1, wherein the bondinglayer of each of said units comprises two bonding portions presentingdistinct breaking forces.
 13. A container having two side walls definingan opening giving access to an inside volume, said container including aclosure system as defined in claim 1 arranged on its side walls so as toform a reclosable opening.
 14. The container according to claim 13,wherein each unit has an internal border and an external border, theinternal border being arranged in the inside volume of the container,and the external border being arranged outside of the inside volume ofthe container, the bonding layer of at least one of the units comprisingan inner portion and an outer portion presenting distinct breakingforces, and is configured so that its inner portion presents a breakingforce that is smaller than the breaking force of its outer portion. 15.The container according to claim 13, wherein each unit has an internalborder and an external border, the internal border being arranged in theinside volume of the container, and the external border being arrangedoutside of the inside volume of the container, the bonding layer of atleast one of the units comprises an inner portion and an outer portionpresenting distinct breaking forces, and is configured in such a mannerthat its outer portion presents a breaking force that is smaller thanthe breaking force of its inner portion.